98737-29-2Relevant articles and documents
Synthesis method of (2S, 3S)-3-(t-butyloxycarboryl amino)-1, 2-epoxy-4-phenylbutane
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Paragraph 0043; 0048; 0049; 0054, (2021/06/23)
The invention relates to the technical field of synthesis of drug intermediates, in particular to a synthesis method of (2S, 3S)-3-(t-butyloxycarboryl amino)-1, 2-epoxy-4-phenylbutane. The method comprises the following steps: condensing N-t-butyloxycarboryl-L-phenylalanine serving as a raw material with substituted phenol under the action of a condensing agent to obtain active ester 15; reacting the active ester 15 with a ylide reagent and alkali to obtain a sulfoxide ylide intermediate 16; reacting the sulfoxide ylide intermediate 16 with halide salt under the action of a catalyst to obtain a halogenated ketone intermediate 6; reducing the halogenated ketone intermediate 6 through a reducing agent under the action of a catalyst to obtain a halogenated methanol intermediate 7; and removing halogen acid from the halogenated methanol intermediate 7 under the action of alkali, and carrying out condensation cyclization to obtain the target product (2S, 3S)-3-(t-butyloxycarboryl amino)-1, 2-epoxy-4-phenylbutane. The synthesis method of the (2S, 3S)-3-(t-butyloxycarboryl amino)-1, 2-epoxy-4-phenylbutane, provided by the invention, has the characteristics of cheap and easily available initial raw materials, safe and controllable process and easiness in operation.
Kinetic study on the reaction of p-tert-butylbenzoic acid with methanol catalyzed by deep eutectic solvent based on choline chloride
Guo, Yuan,Tang, Linmao,Xue, Weilan,Zeng, Zuoxiang
, p. 1241 - 1252 (2021/08/12)
The synthesis of methyl p-tert-butylbenzoate using deep eutectic solvent (DES) as a green catalyst was studied in this work. Four DESs were prepared by combining choline chloride (ChCl) and p-toluenesulfonic acid monohydrate (PTSA) with different molar ratios (1:1–3). It was found that ChCl-1.5PTSA with a molar ratio of 1:1.5 was superior to other DESs both in physical properties and catalytic performance. Therefore, it was selected to carry out the kinetic experiments. The effects of stirring speed, temperature, molar ratio of methanol to p-tert-butylbenzoic acid, and catalyst loading on the conversion of p-tert-butylbenzoic acid were discussed. In addition, the reaction kinetics of p-tert-butylbenzoic acid and methanol with ChCl-1.5PTSA as catalyst was explored in the temperature range of 332.15–349.15 K, and the experimental data were well fitted by pseudo-homogeneous model. Moreover, the recyclability of ChCl-1.5PTSA was evaluated. The result shows that the catalyst could be easily separated from the reaction system without any extractant, and the performance of the catalyst remains stable in multiple times recycling. Therefore, ChCl-1.5PTSA is expected to be an efficient and environmentally friendly catalyst for the methyl esterification of p-tert-butylbenzoic acid with a bright future in industrial application.
Aerobic epoxidation of styrene over Zr-based metal-organic framework encapsulated transition metal substituted phosphomolybdic acid
Hu, Dianwen,Song, Xiaojing,Zhang, Hao,Chang, Xinyu,Zhao, Chen,Jia, Mingjun
, (2021/04/19)
Catalytic epoxidation of styrene with molecular oxygen is regarded as an eco-friendly alternative to producing industrially important chemical of styrene oxide (STO). Recent efforts have been focused on developing highly active and stable heterogeneous catalysts with high STO selectivity for the aerobic epoxidation of styrene. Herein, a series of transition metal monosubstituted heteropolyacid compounds (TM-HPAs), such as Fe, Co, Ni or Cu-monosubstituted HPA, were encapsulated in UiO-66 frameworks (denoted as TM-HPA@UiO-66) by direct solvothermal method, and their catalytic properties were investigated for the aerobic epoxidation of styrene with aldehydes as co-reductants. Among them, Co-HPA@UiO-66 showed relatively high catalytic activity, stability and epoxidation selectivity at very mild conditions (313 K, ambient pressure), that can achieve 82 % selectivity to STO under a styrene conversion of 96 % with air as oxidant and pivalaldehyde (PIA) as co-reductant. In addition, the hybrid composite catalyst can also efficiently catalyze the aerobic epoxidation of a variety of styrene derivatives. The monosubstituted Co atoms in Co-HPA@UiO-66 are the main active sites for the aerobic epoxidation of styrene with O2/PIA, which can efficiently converting styrene to the corresponding epoxide through the activation of the in-situ generated acylperoxy radical intermediate.
